fix: 优化腾讯云账单同步限频

- 全局限制腾讯云API调用频率为每秒4次以内
- 对RequestLimitExceeded增加指数退避重试
- 补充限频回归测试并更新账单同步支持说明

backend/cloud/tencent.go

@@ -3,17 +3,39 @@ package cloud
 import (
 	"encoding/hex"
 	"encoding/json"
+	"errors"
 	"fmt"
 	"io"
 	"net/http"
 	"sort"
 	"strings"
+	"sync"
 	"time"
 )
 
 // TencentProvider 通过腾讯云 TC3-HMAC-SHA256 API 同步 CVM 资源。 // Logan.Li
 type TencentProvider struct{ accessKey, secretKey string }
 
+const (
+	tencentRequestInterval = 260 * time.Millisecond
+	tencentMaxAttempts     = 4
+)
+
+var tencentLimiter = struct {
+	sync.Mutex
+	next time.Time
+}{}
+
+// tencentAPIError 保留腾讯云错误码，便于对限频错误做退避重试。 // Logan.Li
+type tencentAPIError struct {
+	Code    string
+	Message string
+}
+
+func (e *tencentAPIError) Error() string {
+	return fmt.Sprintf("腾讯云 API 错误 %s: %s", e.Code, e.Message)
+}
+
 // tencentInstancesResponse 描述腾讯云 CVM 实例分页响应。 // Logan.Li
 type tencentInstancesResponse struct {
 	Response struct {
@@ -56,6 +78,44 @@ func (p *TencentProvider) callInRegion(region, action string, payload interface{
 
 // callService 使用 TC3-HMAC-SHA256 调用腾讯云服务 API。 // Logan.Li
 func (p *TencentProvider) callService(service, host, version, action, region string, payload interface{}) ([]byte, error) {
+	var lastErr error
+	for attempt := 0; attempt < tencentMaxAttempts; attempt++ {
+		waitTencentRequestSlot()
+		data, err := p.callServiceOnce(service, host, version, action, region, payload)
+		if err == nil {
+			return data, nil
+		}
+		lastErr = err
+		delay, retry := tencentRetryDelay(err, attempt)
+		if !retry {
+			return nil, err
+		}
+		time.Sleep(delay)
+	}
+	return nil, lastErr
+}
+
+// waitTencentRequestSlot 将进程内所有腾讯云请求统一限速在每秒 4 次以内。 // Logan.Li
+func waitTencentRequestSlot() {
+	tencentLimiter.Lock()
+	defer tencentLimiter.Unlock()
+	if delay := time.Until(tencentLimiter.next); delay > 0 {
+		time.Sleep(delay)
+	}
+	tencentLimiter.next = time.Now().Add(tencentRequestInterval)
+}
+
+// tencentRetryDelay 对 RequestLimitExceeded 使用指数退避，其他错误立即返回。 // Logan.Li
+func tencentRetryDelay(err error, attempt int) (time.Duration, bool) {
+	var apiErr *tencentAPIError
+	if !errors.As(err, &apiErr) || !strings.HasPrefix(apiErr.Code, "RequestLimitExceeded") || attempt >= tencentMaxAttempts-1 {
+		return 0, false
+	}
+	return (500 * time.Millisecond) * time.Duration(1<<attempt), true
+}
+
+// callServiceOnce 执行一次腾讯云 TC3-HMAC-SHA256 签名请求。 // Logan.Li
+func (p *TencentProvider) callServiceOnce(service, host, version, action, region string, payload interface{}) ([]byte, error) {
 	body, err := json.Marshal(payload)
 	if err != nil {
 		return nil, fmt.Errorf("编码腾讯云请求失败: %w", err)
@@ -93,6 +153,9 @@ func (p *TencentProvider) callService(service, host, version, action, region str
 		return nil, fmt.Errorf("读取腾讯云响应失败: %w", err)
 	}
 	if resp.StatusCode < 200 || resp.StatusCode >= 300 {
+		if resp.StatusCode == http.StatusTooManyRequests {
+			return nil, &tencentAPIError{Code: "RequestLimitExceeded.HTTP429", Message: string(data)}
+		}
 		return nil, fmt.Errorf("腾讯云 API 返回 HTTP %d: %s", resp.StatusCode, string(data))
 	}
 	var envelope struct {
@@ -104,7 +167,7 @@ func (p *TencentProvider) callService(service, host, version, action, region str
 		} `json:"Response"`
 	}
 	if json.Unmarshal(data, &envelope) == nil && envelope.Response.Error != nil {
-		return nil, fmt.Errorf("腾讯云 API 错误 %s: %s", envelope.Response.Error.Code, envelope.Response.Error.Message)
+		return nil, &tencentAPIError{Code: envelope.Response.Error.Code, Message: envelope.Response.Error.Message}
 	}
 	return data, nil
 }

backend/cloud/tencent_billing.go

@@ -7,7 +7,6 @@ import (
 	"sort"
 	"strconv"
 	"strings"
-	"time"
 )
 
 // FetchDailyBill 拉取指定日期的腾讯云日账单，并按产品和地域汇总。 // Logan.Li
@@ -68,8 +67,6 @@ func (p *TencentProvider) FetchDailyBill(billingDate string) ([]CloudBillingReco
 		if len(response.Response.DetailSet) < pageSize || (response.Response.Total > 0 && offset+pageSize >= response.Response.Total) {
 			break
 		}
-		// 腾讯云账单接口频率上限为每秒 5 次，分页请求限速为每秒 4 次。 // Logan.Li
-		time.Sleep(250 * time.Millisecond)
 	}
 
 	keys := make([]aggregationKey, 0, len(aggregation))

backend/cloud/tencent_test.go

@@ -0,0 +1,28 @@
+package cloud
+
+import (
+	"errors"
+	"testing"
+	"time"
+)
+
+// TestTencentRetryDelay 验证限频错误指数退避与最大重试次数。 // Logan.Li
+func TestTencentRetryDelay(t *testing.T) {
+	rateLimitErr := &tencentAPIError{Code: "RequestLimitExceeded", Message: "frequency limit"}
+	delay, retry := tencentRetryDelay(rateLimitErr, 0)
+	if !retry || delay != 500*time.Millisecond {
+		t.Fatalf("首次限频退避错误: retry=%v delay=%s", retry, delay)
+	}
+
+	delay, retry = tencentRetryDelay(rateLimitErr, 2)
+	if !retry || delay != 2*time.Second {
+		t.Fatalf("第三次限频退避错误: retry=%v delay=%s", retry, delay)
+	}
+
+	if _, retry = tencentRetryDelay(rateLimitErr, tencentMaxAttempts-1); retry {
+		t.Fatal("达到最大次数后不应继续重试")
+	}
+	if _, retry = tencentRetryDelay(errors.New("鉴权失败"), 0); retry {
+		t.Fatal("非限频错误不应重试")
+	}
+}

backend/pkg/systask/registry.go

@@ -69,7 +69,7 @@ var (
 		},
 		{
 			Code: "cloud_billing_sync", Name: "云账单同步",
-			Description: "从云账号 AK 拉取昨日账单（按产品+地域），写入云账单管理；当前支持阿里云",
+			Description: "从云账号 AK 拉取昨日账单（按产品+地域），写入云账单管理；当前支持阿里云和腾讯云", // Logan.Li
 			Schedule: "每天 10:30", Category: "finops", Runnable: true, Enabled: true,
 		},
 	}

frontend/src/components/cloud/CloudBilling.tsx

@@ -125,7 +125,7 @@ export function CloudBilling() {
     if (activeTab === 'alerts') loadRules();
   };
 
-  // 从云账号 AK 同步昨日账单（当前支持阿里云） // Logan.Li
+  // 从云账号 AK 同步昨日账单（当前支持阿里云和腾讯云） // Logan.Li
   const handleSyncYesterday = async () => {
     setSyncing(true);
     try {